Container with flexible cover



y 1961 1. P. FLORSHEIM, JR 2,984,382

CONTAINER WITH FLEXIBLE COVER Filed May 14, 1959 CONTAINER WITH FLEXIBLE COVER Ivan P. Florsheim, Jr., 22 W. Monroe St., Florsheim Manufacturing Co. Inc., Gleucoe, Ill.

Filed May 14, 1959, Ser. No. 813,236

4 Claims. (Cl. 22060) This invention relates to a flexible normally-covered container and, more particularly, to a flexible cover and container combination with a unique interaction between the cover and container which permits covering the container without displacing any of the contents thereof, provides an eflicient fluid seal between the two parts, substantially locks the two parts together, and yet permits ready and convenient removal of the cover when desired.

There are numerous types of containers with plastic covers commercially available at the present time for the packaging of food products and the like. Despite the high state of development of such containers, however, all suffer from one or more shortcomings which render them unsuitable for some applications and/or inconvenient and/or costly to use. For example, some do not provide a satisfactory liquid and vapor seal between the cover and container. Others do not provide a positive lock between the cover and container so that the cover can withstand substantial forces without popping off when, for example, the container is turned upside down and contents bear down on the cover, the sides are squeezed in handling, or internal pressure is generated by thermal expansion or vaporization of contents and/or the like. Still others, which do provide locking contact between cover and container, are diflicult to uncover without employing tabs or finger grips for such purpose. Still others have recessed covers which prevent the container from being covered without displacing some of the contents, thereby decreasing capacity and not permitting the convenient practice of rim scraping, i.e., overfilling and then eliminating excess by merely scraping the contents flush with the rim. Still others do not provide lateral support for the mouth of the container to prevent excessive inward deformation under stress with consequent disruption of the liquid and vapor seal and displacement of the contents.

It is, therefore, an object of the present invention to provide a novel container and flexible cover combination which is substantially free of all of the aforementioned shortcomings.

Specifically, it is an object of the present invention to provide a container and flexible cover which has an efficient gas and liquid seal between the container and cover, substantially locks the cover to the container, and yet permits ready and convenient manual removal of the cover.

It is a further object to provide a scalable container with flexible locking cover wherein the cover laterally supports and fits flush with the brim of the container without substantially displacing any of the contents thereof, thereby permitting the practice of rim scraping when filling the container.

These and other objects of the present invention will become apparent from the following detailed description and specific claims.

To achieve these objects, a container and cover combination is provided wherein the container has a wall portion with upper edges defining the mouth, said upper atent C) ice edges having a peripheral external bead thereon. The flexible cover has a substantially-flat covering web with a peripheral downwardly-depending flange with external and internal surfaces. The external surface preferably is peripherally grooved at the junction of the flange with the covering disc. The internal surface of the flange has a lower portion which slopes upwardly and inwardly and an upper portion which has an internal peripheral groove suitable for sealing contact with the bead of the container. The covering disc also has a discontinuous downwardly depending lip internal of and in spaced relation from said flange so as to form with the internal peripheral groove of the flange a locking slot for the bead of the container, said slot having a discontinuous annular mouth narrower than the transverse cross section of the bead.

The container and cover combination of the present invention may be manufactured from a flexible, distortable plastic such as a solid polyolefin, e.g., polyethylene, polypropylene, or the like. While both. the container and cover may be formed from such materials, the container may preferably be constructed from a more-rigid material than the flexible cover portion, e.g., a substantially rigid polystyrene plastic. A more-rigid material for the container is preferred because of the greater structural strength associated therewith. As will become apparent from the detailed description hereinafter, the cover must necessarily be sufflciently flexible to permit momentary distortion of the flange and/or locking lips when forcing the cover over the head of the container mouth.

The container and cover combination of the present invention may have any desired configurations. For example, it may be cylindrical, truncated, polygonal, or the like. In a particular and preferred embodiment, to be described in detail hereinafter, it is multisided with intermediate rounded sections, and in such case, the downward depending lip of the cover extends only along portions of the straight sections.

The present invention will be more clearly understood from the following detailed description of a particular and preferred embodiment thereof, read in conjunction with the accompanying drawing wherein:

Figure 1 shows the container and cover in the normally-covered condition with a portion of both cut away for greater clarity;

Figure 2 portrays the underside of the cover and shows the discontinuous locking lips and their relationship to the flange;

Figure 3 presents a magnified stctional view taken along sectional lines 3-3 of Figure 1 and shows the unique interaction between the bead of the container mouth and the inner surfaces of the flange and locking lips of the cover, and

Figure 4 presents a magnified sectional view taken along sectional lines 44 of Figure 1 and shows the interaction between the bead of the container mouth and the inner surfaces of the flange at a point intermediate the discontinuous locking lips of the cover.

Referring to Figure 1, the present invention includes container 10 and cover 11. In this embodiment, container 10 is manufactured from substantially-rigid polystyrene, and cover 11 is manufactured from flexible solid polyethylene. Container 10 has a dished-out bottom 12 and a wall portion 13, optionally expanded outward at 13a so as to form an internal upwardly-facing, annular shoulder 13b, whereby a plurality of such containers may be nested and stacked when uncovered. The rim of the wall portion contains a continuous head 14, which interacts with portions of cover 11 so as to form a fluid seal around the entire rim, as will be described in detail hereinafter.

Cover 11 comprises a fiat covering web 15 and a peripheral downwardly depending flange 16, the exterior surface 17 of said flange optionally having a groove 17a at the junction of the flange with the covering web. Covering web 15 also contains a discontinuous downwardly depending lip 18 internal of and in spaced relation from flange 16 so as to form a locking slot for bead '14 of container 10, as will be further described hereinafter.

Figure 2 is a view of the underside of cover 11 and clearly shows the discontinuity of the downwardly depending lips 18 and how the lips extend only along portions of the straight sections of flange 16. .It also shows the spaced relationship of lips 18 with respect to flange 16 and how the extremities 18a of each lip portion are flared away from the flange to facilitate ease ofcovering and uncovering the container.

Figure 3 is a magnified sectional .viewofa portion of container and cover 11 taken along sectional line 3-3 of Figure 1, which view includes lips .18 of the .cover. It can be seen from Figure 3 that flange 16 has an external surface 17 which, as previously mentioned, may optionally contain peripheral groove 17a. Theinternal surface of flange 16 has a lower portion 19, which slopes upwardly and inwardly and an upper portion 20 which forms an internal peripheral groove having a plurality of flat contacting surfaces which are suitable for sealing contact with bead 14 of the container. As shown in Figure 3, downwardly depending lip 18 and groove 20 form a locking slot for, as well as a seal with, bead 14. For such locking purposes, the mouth of the locking slot is smaller than the bead.

Figure 4 is a magnified sectional view of va portion of container 10 and cover 11 taken along. section line 44 of Figure 1. This sectional view is intermediate disconforming a liquid and vapor seal. The lower portion 19 of the internal surface of flange 16 is also normally dimensioned so that the sloping surface acts as a wedge and forces the flange outwardly and upwardly, when the cover is forced down over bead 14 of the container. Since the flange must thus be flexed or otherwise distorted when covering or uncovering the container, it is apparent why at least the flange of the cover must necessarily be flexible. Groove 17a in external surface 17 of flange 16 lends additional flexibility to the flange for this purpose as well as providing an ornamental outline for the covering web.

The wedge function of sloping surface 19 is particularly important along those portions of the-flangead- -jacent downwardly-depending locking lips 18. As previcusly mentioned, the cover is so designed that the mouth of the discontinuous annular locking slot formed ,by groove 20 and locking lips 18 is smaller than bead 14. Thus, flange 16 must be outwardly wedged sufl"1 ciently to permit entry of the bead into the locking slot. Entry of the bead into the slotmay also be facilitated somewhat by slight flexure of lips 18 inwardly. Because of the relative rigidity of lips 18 as compared with flange 16, expansion of the mouth of the locking slot is pri- -marily accomplished by the outward wedging of the flange. Once the bead enters the slot, it is locked therein, of course, by contraction of the mouth due to the normal resiliency of the plastic.

It is apparent from consideration of Figures 1 through 4 that the locking slots formed by groove 20 and locking lips 18 perform a dual function. In addition to locking the cover to the container, they contribute substantial inwardly when any substantial force is applied adjacent the brim, such as would occur, for example, when the container is lifted by grasping the sides thereof. At the corners of the container intermediate the locking lips such inward support is not required because of the natural rigidity associated with the rounded surfaces.

Because locking lips 18 ,are not extended along the entire underside of covering disc 15, the cover may be readily removed from the container merely by peeling it outwardly and upwardly at the rounded corners. For such purpose, a finger or fingernail maybe inserted beneath flange 16 and/or between flange 16 and wall portion 13a, adjacent/a corner of the covered container. By lifting upwardlyand outwardlyat this point the seal between the cover and the container is broken, thus avoiding formation of a partial vacuum as the cover is lifted. By so peeling the cover from the container, the bead readily slips out of the locking slots formed by groove 20 and locking lips 18, the flared extremities 18a of the lips facilitating same. Despite .the,. ease withwhichthe cover may thus be peeled from .the ,containenthoCQVfir is normally firmly locked to the container ,so that only a very substantial forcecan wrestthe .cover. {The normally-encountered internal pressures caused by thermal expansion, vaporization of .the contents,,or thelike are usually not suflicient to break the lock. Also because of the locking lips, thecontainermay be turned upside down, and thecontents thereofwould be fully supportable by the cover itself.

.eflicient gas and liquid sealbetween the container and cover, provides means for locking the .CQY rto the.,container, and yet permits ready ,and convenient manualremoval of the coverwhendesired. At the same time,,t,h,e cover provides lateral supportfor thesidesof the container and the covering web of the cover issubstantially flush with the rim of the container, so that thecontainer may be filled to the brim and coveredwithout displacing any of the contents. It. is therefore manifest thatthe objects of this invention have been achieved.

While the present invention has been described inconnection with a specific embodiment thereof ieshould be understood, of course, that the invention is notlimited thereto. Many alternative modificationsof the present invention will be apparent from the above description. to those skilled in the art, and.suchmodificationsare .considered within the. scope andspirit of. the, present juvention.

Having thus described the invention, what is claimed is:

1. A fill-to-the-brim polystyrenecontainer and polyethylene locking cover therefor, said container having a wall portion withupper edge defining the mouth of the,

containenand having a peripheral external bead therfeon, said wall portion of said containerxpahdirigbtitwardly from the bottom to the mouth. thereof and including a continuous rim offset outwardly to'forinan'finternaL upWardIy-facing, annular shoulder, said cover having a substantially flat covering disc and a peripheral, downwardly-depending'fiange, said flange having externaland internal surfaces,the external surface of said flange being peripherally grooved at the junction of said.,flange with said flat covering disc, the lower portion, of the internal surface of said flange being sloped upwardly .anclfir'twardly and the upper portion having a peripheral .internal groove suitable for sealing contact 'withsaid bead of said container, said cover also having a discontinuous downwardly-depending lip in spaced relationffrorn said flange so as to form with said internal groove alo cking slot for said bead, said slot havir'ig'a discontinuoii'slfannular mouth narrower than said b'eadl N 2. The container and cover of claim 1...Wherein. said wall portion and said flange are multisided with intermediate rounded sections and saiddownwardly-depending lip extends only adjacent the straight sections of said flange.

3. The container and cover of claim 1 wherein the extreme peripheral distance of said lower portion of the internal surface of said flange is greater than the extreme peripheral distance of said peripheral external bead and the minimum peripheral distance of said lower portion of the internal surface of said flange is less than the extreme peripheral distance of said peripheral external bead, whereby said flange is wedged outwardly momentarily, when the cover is pressed on to the container.

'4. A fill-to-the-brim-type container and flexible locking cover therefor, said container having a wall portion with free edges defining the mouth of the container and having a peripheral, external bead thereon, said wall portion of said container being multisided with corner sections intermediate the straight sections, said flexible cover having a substantially flat covering web and a peripheral depending flange with corresponding straight and corner sections, said flange having external and internal surfaces, the free portion of the internal surface being sloped inwardly and toward said web and the portion adjacent said web having a peripheral groove suitable for sealing contact with said bead of said container,

said cover also having a discontinuous lip in spaced relation from said flange and extending only adjacent straight sections of said flange so as to form with said groove a discontinuous locking slot for said bead, said slot having a mouth narrower than the transverse cross section of said bead, said discontinuous lip having extremities flared away from said flange to provide end portions of said slot which are wider than the transverse cross section of said head.

References Cited in the file of this patent UNITED STATES PATENTS 353,147 Lederle Nov. 23, 1886 1,526,884 Urann Feb. 17, 1925 1,957,804 Reich May 8, 1934 2,419,616 White Apr. 29, 1947 2,695,115 Roop Nov. 23, 1954 2,754,866 Coltman July 17, 1956 2,768,667 Hill Oct. 30, 1956 2,837,236 Betner June 3, 1958 2,851,713 Tupper Sept. 16, 1958 OTHER REFERENCES 808,492 Great Britain Feb. 4, 1959 

